import { Base64 } from './base64.js'
import { util } from './crypto.js'
import { HMAC } from './hmac.js'
import { SHA1 } from './sha1.js'

// 下面这3个信息必填
const url = 'https://hengxinyangkong.oss-cn-shenzhen.aliyuncs.com/'
const OSSAccessKeyId = 'LTAI5tHG1ie9DWcfQhHMgt1U'
const OssAccesskeySercet = 'RvIcgaKHWvQ3IeVHGKO18ROYVPcNDI';


const policyText = {
	"expiration": "2034-01-01T12:00:00.000Z", // 设置Policy的有效期，格式为UTC时间。如果Policy失效，将无法上传文件。
	"conditions": [
		["content-length-range", 0, 1048576000] // 限制上传文件的大小，单位为字节，此处限制文件大小为1 GB。如果上传的文件大小超过此限制，文件将无法上传到OSS。如果未设置该限制，则默认文件大小最大为5 GB。
	]
}

const policy = Base64.encode(JSON.stringify(policyText))
const bytes = HMAC(SHA1, policy, OssAccesskeySercet, { asBytes: true })
const signature = util.bytesToBase64(bytes)

// 生成文件名随机字符串
function random_string(len) {
	const strLeng = len || 32;
	const chars = 'ABCDEFGHJKMNPQRSTWXYZabcdefhijkmnprstwxyz2345678';
	const maxPos = chars.length;
	let pwd = '';
	for (let i = 0; i < strLeng; i++) {
		pwd += chars.charAt(Math.floor(Math.random() * maxPos));
	}
	return pwd;
}

// 获取文件后缀
function get_suffix(filename) {
	const pos = filename.lastIndexOf('.')
	let suffix = ''
	if (pos != -1) {
		suffix = filename.substring(pos)
	}
	return suffix;
}

// dir格式：'img/'
const ossUpload = (filePath : any, name : any, dir : any) => {
	const key = dir + random_string(10) + get_suffix(name)
	return new Promise((resolve, reject) => {
		uni.uploadFile({
			url,
			filePath,
			name: 'file',
			formData: {
				name,
				key,
				policy,
				OSSAccessKeyId,
				success_action_status: '200',
				signature
			},
			success: () => {
				resolve({ success: true, data: url + key })
			},
			fail: () => {
				reject({ success: false, data: '上传失败' })
			}
		})
	})
}

export default ossUpload;